Piston-ring.



pointed out the' ARTHUR CHEVROLET, OF JACKSON, MICHIGAN.

rvIsToN-RING.

Specification of Letters Patent.

Patented Apr. 21, 1914.

Application filed March 21, 1913. Serial No. 755,926.

"Tofn'ZZ 'whom t may concern new and useful Improvements in Piston--Rings, of which the following is a specification, reference being hadtherein to the accompanying drawings.

This invention relates to improvements 1n metal packing rings for thepistons of engines, pumps, and similar machines, and more particularlyto packing rings for pistons of internal combustion engines, the objectof the invention being to provide a construction which is such that thering will remain tight at all times, automatically adjusting itself toconditions and providmg for wear of the part-s in use.

The invention consists in the matters hereinafter set forth, and moreparticularly claims,reference being had to the accompanying drawings inwhich- Figure l is a side elevation of a portion of a piston i whichrings embodying the invention are applied; Fig. 2 is a side elevation ofa portion of one of the rings detached; Fig. 3 is a plan view of aportion of one of the rings showing the lap joint; Fig. 4 is a sideelevation of the same illustrating the position which the ring will takewhen the ring is compressed to overlapl the ends; Fig. 5 is a viewsimilar to Fig. 4 showing the ring in place on a portion of the pistonand illustrating the manner in which the ring is turned down to fitwithin the groove of the piston. Fig. 6 iS a side elevation of a4portion of a piston showing rin gs applied thereto of a modifiedconstruction. Fig. 7 is a transverse section of Fig. 6 on the line :vand Fig. 8 is an edge view of a pair of rings ydetached and in openposition.

There is always more or less leakage past packing rings of the usualconstruction having overlapping or abutting ends due to the fact that asthe rings wear away on their outer face in use, the ends separate andthus permit the luid under compression to leak through. The object ofthis invention `.is to so construct the overlapping ends of the ringthat as the ring wears away in use and it opens out, the ends will stillbe held firmly in contact with each other and thus prevent leakage.These rings are formed by cutting portions of the desired length to fermthe-ring 1 from a formed tubular body, irr the usual manner, and thering is then severed. A groove 2 is cut in the outer face of the ringextending circumferentially from one of the severed ends `and cuttingthrough one side edge of the ring. The opposite end of the ring isformed with a tongue 3 of a width exactly the same as the width of thegroove, the side of the ring adjacent to the tongue being cut awaysothat the tongue will fit within the groove when the ring is compressedas is shown in Fig. 4, bringing the ends into overlapping relation. Theside of the tongue which is adapted to contact the bottom of the groove,is cut away at 4 near the base of the tongue, thus leaving a roundedprojecting portion 5 adjacent to the outer end of the tongue adapted torest upon the bottom of the groove.

'When the ends of the ring have been formed with the groove andtonguehas described, the ringis then compressed to bring the tongue intothe groove as shown in Fig. 4. This distorts the ring and itsoverlapping ends project slightly beyond the outer face of the ring.Therefore, inrorder to make the ring fit perfectly within the cylinderin whichit is adapted to operate, it is necessary to true up the outerface of the ring while it isheld with -its ends in overlapping relation.In Fig, 5 the ring is shown in full size as having been faced '0H inthis manner to a true circle, the dotted lines indicating the part whichhas been cut away. f

AWhen the groove 2 is formed, its bottom is cut concentric with theouter face of the ring but after theends have been overla ped and thering turned down to a true circle on its outer faceftlie cutting away cfthe outer face of the end in which the groove is formed, makes thisgroove deeper at its, inner end than it is at the end of the ring owingto the fact that the ring when compressed before being turned to itstruecircle on its outer face, assumes a slightly/.oval

shape and therefore when the ring is turned to a true circle while beingso held, thegreatest amount of metal is cut away from i that portion.which projects beyond the true been formed up as de awayin use, ,theoverlappingendslvvillLmoveV upon each other owing to the tendency of thering to open out, and its outer face will thus be held closely againstthe surface of the cylinder, making a tight. joint. As the ring thusopens out the tongue 3 slides along the groove 2 and as the bottom ofthe groove lis eccentric tothe outer face of the ring, or, inotherwords, the groove is deeper at its inner end thanl it is at theextreme end of lo' the ring, the tongue 3 will be constantly held L incontact with the bore of the cylinder as theprojection 5 moves up theinclined ,b ot- 4"tom, of the groove. The end of the ring "thawing 'thegroove is more rigid than the 'tongue and it will therefore exert astrong constant pressure outwardly upon the tongue to hold said tonguein firm contact with the bore of the cylinder. By cutting away thetongue at its inner side, it may project into the groove and itscontacting portion 5 may engage the bottom of the groove at a conjsiderable distance from the end of the ring without the base of thetongue coming in i contact with the bottom of the groove, and thus thetongue will always contact the bottom of the groove at one point andgive a tight joint.

The rings are preferably placed in pairs upon the piston a with therings of each pair "oppositely arranged, that is with the tongue 'S ofeach ring arranged at the side thereof l adjacent to the other ring ofthe pair. The lcontinuous side of one of the rings which `Eis formed bythe tongue on one end overlapping the reduced opposite end of the iring, is therefore held in close contact with the side of the groove inwhich it is placed to prevent leakage, during the movement of the pistonin one direction and said side 40 surface of the other ring willlikewise be i held in contact with therside of the groove during themovement of the piston in the opposlte direction.

In Figs. 6 to 8 inclusive a modified construction is-shown in which eachring is made up of a pair of rings, one ring 6 of each pair being formedwith overlapping ends and the other ring 7 being formed with abuttingends. The ring 6 is cut away at one end as 'at 8 to `form a seat similarto the groove 2 of the construction shown in Fig. 5, for the tongue 9which is formed on the opposite end of the ring, said tongue beingsimilar to the tongue 3 and 'provided with the projecting contactportion 5 to engage the seat-on the opposite end of the ring and cutaway at the base of thetongue as at tso that said tongue will notContact thc opposite end of` the ring. The ring 6 lies in do contactwith the side of the ring 7 and in such relation thereto as to breakjoints therewith, that is, the overlapping ends of the ring G arepositioned at a considerable distance from the abutting ends 10 of thering The rings are held in their relative position by means of a pin orwedge 11 fitting within notches in the adjacent sides of the two ringsand thus preventing the rings from turning relatively upon the piston.

Obviously, changes may be made in the construction and arrangement ofparts without departing from the spirit of my invention and I do nottherefore limit myself to lthe particular form or construction shown.

What I claim as my invention is l. A packing ring for pistons comprisingsplit ring one end of which is eut away at the outer side to form aseating surface eccentric to the outer surface of the ring, and aprojecting end portion on the opposite end of the ring having anenlargement to engage said seating surface.

Q. A packing ring for pistons comprising a split ring formed at one endwith a seating surface, and provided at its opposite end with a tongueto overlap said seating surface, said tongue being formed with anenlargement near its free end to engage said seating surface.

3. A packing ring for pistons comprising a split ring formed with an endportion having an outer surface formed eccentric to the outer surface ofthe ring, and a tongue on the opposite end of said ring having aninwardly projecting .portion adjacent to the free end of the tongue toengage said surface of said end portion of the ring.

4. A packing ring for pistons comprising a split ring having an endportion of lesser thickness than the thickness of the ringand formedwith an outer surface inclined inwardly of the ring from the free end ofsaid end portion, and a tongue on the opposite end of said ring cut awayat the inner side thereof adjacent to the base of the tongue and formingan enlargement adjacent to the free end of the tongue to engage saidinclined surface of said end por tion. j

5. A packing ring for pistons comprising a pair of split rings arrangedside by side with their edges in contact and cach provided with a notchin its side adjacent t0 the other ring, a pin in said notches to preventrelative turning of said rings, one ring of each pair being formed withan end por tion which is of lesser thickness than the' body of the ringand is formed with an outer surface eccentric to the outer surface ofthe ring, and a tongue. on the opposite end of said ring to overlap saidreduced end and having an inwardly projecting portion to engage the saidouter surface of said `reduced end.

G.. A packing ring comprising a split ring having ends so shaped as topresent projecting portions on the periphery of said ring requiringtrimming before the periphery of said ring is constructed.

7. A packing ring comprising a resilient split ring having its endsplaced together in a .manner as to compress and distort said ringwhereby the ends of said ring Will project from theperiphery thereof andrequire trimming before the periphery of said ring is constructed.

8. A packing ring comprising a resilient split ring having its endsplaced together in s .manner :is to compress and distort said ring, andineens in connection with the ends i of said ring for expanding saidring as the periphery thereof is worn.

In testimony whereof I aix my signature in presence of two Witnesses.

ARTHUR CHEVROLET- Witnesses:

ERNEST E. PIERCE, JOHN B. Foo'm,

